In one known form of high load power transmission belt, relatively hard blocks are secured to the flexible looped belt for engagement with the sidewalls of the pulley grooves in transferring power between the pulley and belt structure. The blocks are secured to the belt seriatim longitudinally of the belt by suitable securing means, such as bolts, rivets, etc., extending through the block and belt.
In one improved form of such high load power transmitting belt, blocks are provided on opposite sides of the belt, with the block-securing means serving to clamp the belt therebetween.
The blocks conventionally extend fully across the belt and define side edge faces having facial engagement with the opposed surfaces of the pulley groove.
A problem arises in such high load transmission belts in that substantial heat is generated in the operation thereof. The heat has been found to be developed as a result of the flexing of the belt material, the friction between the blocks and the flexible belt portion, and friction between the bolt and pulley and groove surfaces.
Such increased temperature of the belt causes degradation of the belt materials, reduced desired adhesion between the tensile cords of the belt and the cover in which the tensile cords are embedded, wear of the belt materials, softening of the blocks, etc., resulting in a shortened useful life of the belt.